From Adelaide, where he played at underage levels for the Craigmore Cricket Club, Head represented South Australia at both under-17 and under-19 level, making his debut in the National Under-19 Championships at the age of 17. After making his name playing grade cricket for Tea Tree Gully Cricket Club, Head made his first-class cricket debut for South Australia in the Sheffield Shield at the age of 18 in early 2012. He made a promising start to his career with three matches for South Australia, scoring his maiden half-century in his second match and falling short of scoring his maiden century in his third match with 90 runs against Tasmania. He was rewarded at the end of the season with a rookie contract with South Australia.

He went on to play 18 under-19 One Day International (ODI) matches for the Australian national team, including at the 2012 Under-19 Cricket World Cup. He impressed with both bat and ball during the tournament, scoring 87 off 42 balls against Scotland and taking three wickets against Bangladesh in the quarter-final. He showed leadership qualities when he captained South Australia to victory in the 2012–13 National Under-19 Championships, being named Player of the Championship for the second consecutive year.

Head remained a regular selection for the 2012–13 season, usually batting in the middle order. He came close to scoring his maiden century with 95 against Western Australia. Though he was not dismissed, he ran out of batting partners and was stranded at the crease five runs short of the milestone. He subsequently played a single Twenty20 game for the Adelaide Strikers in the Big Bash League, replacing the injured Kieron Pollard in the team. Shortly after South Australia's Shield win against Victoria in January 2013, he was hit by a car outside a hotel in Adelaide, receiving injuries to his head and back, but he made a full recovery and was able to return for South Australia's next match. Head was one of six young Australian players to be part of the inaugural Ageas Bowl International Cricket Academy during the 2013 season, training at the ground's facilities.

In the early part of Head's career he struggled to reach his maiden first-class century, instead finishing with scores in the nineties on multiple occasions. After his score of 90 in his debut season and his unbeaten 95 against Western Australia in 2012, he made it to the nineties three times in the 2013–14 Sheffield Shield season, against Western Australia twice more and once against Tasmania with scores of 92, 98 and 98 respectively. Despite this he was able to score a List A century for the National Performance Squad against South Africa A in July 2014.